@layer base, layout, components, utilities;

@layer base {
  :root {
    /* Fallbacks for OKLCH */
    --bg-primary-fallback: #f8f9fa;
    --bg-secondary-fallback: #f1f3f5;
    --text-primary-fallback: #212529;
    --text-muted-fallback: #868e96;
    --accent-fallback: #339af0;
    --accent-hover-fallback: #228be6;
    --glass-bg-fallback: rgba(255, 255, 255, 0.7);
    --glass-border-fallback: rgba(0, 0, 0, 0.1);
    --shadow-color-fallback: rgba(0, 0, 0, 0.1);

    /* OKLCH Color Palette */
    --bg-primary: oklch(98% 0.01 200);
    --bg-secondary: oklch(95% 0.02 200);
    --text-primary: oklch(20% 0.02 200);
    --text-muted: oklch(50% 0.02 200);
    --accent: oklch(65% 0.15 250);
    --accent-hover: oklch(60% 0.18 250);
    --glass-bg: oklch(100% 0 0 / 70%);
    --glass-border: oklch(100% 0 0 / 20%);
    --shadow-color: oklch(0% 0 0 / 10%);
    
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --border-radius-lg: 1.5rem;
    --border-radius-md: 0.75rem;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  }

  :root.dark {
    /* Dark Fallbacks */
    --bg-primary-fallback: #1a1b1e;
    --bg-secondary-fallback: #25262b;
    --text-primary-fallback: #f8f9fa;
    --text-muted-fallback: #adb5bd;
    --accent-fallback: #4dabf7;
    --accent-hover-fallback: #74c0fc;
    --glass-bg-fallback: rgba(26, 27, 30, 0.8);
    --glass-border-fallback: rgba(255, 255, 255, 0.1);
    --shadow-color-fallback: rgba(0, 0, 0, 0.4);

    --bg-primary: oklch(20% 0.02 200);
    --bg-secondary: oklch(15% 0.02 200);
    --text-primary: oklch(95% 0.01 200);
    --text-muted: oklch(70% 0.01 200);
    --accent: oklch(75% 0.15 250);
    --accent-hover: oklch(80% 0.18 250);
    --glass-bg: oklch(20% 0.02 200 / 80%);
    --glass-border: oklch(100% 0 0 / 10%);
    --shadow-color: oklch(0% 0 0 / 40%);
  }

  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  body {
    font-family: var(--font-family);
    color: var(--text-primary-fallback);
    color: var(--text-primary);
    background-color: var(--bg-primary-fallback);
    background-color: var(--bg-primary);
    height: 100vh;
    overflow: hidden;
    line-height: 1.5;
    position: relative;
  }

  body::before {
    content: "";
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
    background-size: 150px;
    background-repeat: repeat;
    opacity: 0.03;
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -1;
  }
}

@layer layout {
  .app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
    gap: 1rem;
    padding: 1rem;
  }

  .sidebar {
    width: 320px;
    display: flex;
    flex-direction: column;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--glass-border-fallback);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(20px);
    background: var(--glass-bg-fallback);
    background: var(--glass-bg);
    box-shadow: 0 10px 40px var(--shadow-color-fallback);
    box-shadow: 0 10px 40px var(--shadow-color);
    transition: var(--transition);
    flex-shrink: 0;
  }

  .editor-area {
    flex-grow: 1;
    border-radius: var(--border-radius-lg);
    background: var(--bg-secondary-fallback);
    background: var(--bg-secondary);
    box-shadow: 0 10px 40px var(--shadow-color-fallback);
    box-shadow: 0 10px 40px var(--shadow-color);
    overflow: hidden;
    position: relative;
    container-type: inline-size;
  }

  @media (max-width: 768px) {
    .sidebar {
      width: 80px;
      padding: 0.5rem;
    }
    .logo, .search-container, .note-content-preview {
      display: none;
    }
  }
}

@layer components {
  /* Sidebar Components */
  .sidebar-header {
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .header-actions {
    display: flex;
    gap: 0.75rem;
    align-items: center;
  }

  .logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    color: var(--accent-fallback);
    color: var(--accent);
  }

  .icon-btn, .icon-btn-outline {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    border: none;
  }

  .icon-btn {
    background: var(--accent-fallback);
    background: var(--accent);
    color: white;
    box-shadow: 0 4px 12px var(--shadow-color-fallback);
    box-shadow: 0 4px 12px var(--shadow-color);
  }

  .icon-btn-outline {
    background: transparent;
    border: 1.5px solid var(--accent-fallback);
    border: 1.5px solid var(--accent);
    color: var(--accent-fallback);
    color: var(--accent);
  }

  .icon-btn:hover {
    transform: scale(1.1);
    background: var(--accent-hover-fallback);
    background: var(--accent-hover);
    box-shadow: 0 6px 20px var(--accent-fallback);
  }

  .icon-btn-outline:hover {
    background: rgba(100, 100, 255, 0.1);
    transform: rotate(15deg);
  }

  .search-container {
    margin: 0 1rem 1.5rem;
    position: relative;
  }

  .search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    color: var(--text-muted-fallback);
    color: var(--text-muted);
  }

  #search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border-radius: var(--border-radius-md);
    border: 1px solid rgba(0, 0, 0, 0.05);
    background: rgba(0, 0, 0, 0.03);
    color: var(--text-primary-fallback);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition);
  }

  #search-input:focus {
    background: white;
    border-color: var(--accent-fallback);
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(100, 100, 255, 0.1);
  }

  /* Note List */
  .note-list {
    flex-grow: 1;
    overflow-y: auto;
    padding: 0 0.75rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
  }

  .note-item {
    padding: 1rem;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
    user-select: none;
  }

  .note-item:hover {
    background: rgba(0, 0, 0, 0.05);
  }

  .note-item.active {
    background: white;
    border-color: var(--glass-border-fallback);
    border-color: var(--glass-border);
    box-shadow: 0 4px 12px var(--shadow-color-fallback);
    box-shadow: 0 4px 12px var(--shadow-color);
  }

  .note-title-preview {
    font-weight: 600;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-primary-fallback);
    color: var(--text-primary);
  }

  .note-content-preview {
    font-size: 0.85rem;
    color: var(--text-muted-fallback);
    color: var(--text-muted);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }

  /* Editor (Custom Element placeholder styles) */
  note-editor {
    display: block;
    height: 100%;
    width: 100%;
  }
}

@layer utilities {
  .glass {
    background: var(--glass-bg-fallback);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border-fallback);
    border: 1px solid var(--glass-border);
  }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-thumb {
  background: var(--text-muted-fallback);
  background: var(--text-muted);
  border-radius: 10px;
}
::-webkit-scrollbar-track {
  background: transparent;
}